Brompton has reported a jump in annual sales and profits as commuters in crowded cities such as Seoul and Tokyo get the folding bike bug.

Profits at the London based bike manufacturer surged nearly 50% to £1.6m in the year to 31 March while sales rose by a quarter to £16.7m.

The company's managing director, William Butler-Adams, said Brompton had clocked up growth of more than 20% in South Korea and Japan as frustrated city-dwellers sought ways to beat traffic jams.

Brompton is one of only two major frame manufacturers still based in the UK and its distinctive bike is named after the Brompton Oratory – a Roman Catholic church in South Kensington, which the company's founder, Andrew Ritchie, could see from the window of his flat as he worked on the prototype in the early 1980s.

Since Butler-Adams took charge a decade ago, the company has expanded rapidly abroad, with production set to increase from 31,000 to 36,000 units in the current financial year.

International sales make up 75% of Brompton's turnover, but the company is aiming for 80% and recently opened its first shop in mainland China, targeting affluent urbanites in Shanghai.

Brompton is also exploring growth avenues such as cycling accessories, including bags and jackets, plus a bike hire scheme – Brompton Dock.

The scheme is expected to be operating in 17 UK train and tube stations by the end of this year.

Cash reserves more than doubled to £2.3m during the period, with the company stating it would increase the dividend payment to shareholders to £3.75 this year, the equivalent of £277,493.